In a Positron Emission Computed Tomography (PET) device, an isotope-labeled drug (such as an imaging agent) having positron emission capability is injected into a subject. The isotope-labeled drug may be, for instance, one or more of a carbon isotope, a fluorine isotope, an oxygen isotope, and a nitrogen isotope. The isotope-labeled drug may participate in a physiological metabolism of the subject and an annihilation event can occur during the physiological metabolism.
FIG. 1 is a schematic diagram of an example PET detector 100. An annihilation event in a subject 102 generates two gamma photons each having an energy of approximately 0.511 MeV and moving in opposite directions.
Since an ability of respective parts of the subject to absorb the isotope-labeled drug can differ, a concentration of the isotope in the respective parts of the subject can be different and an intensity of respective gamma photons generated by annihilation events can also be different. The PET detector 100 surrounding the subject 102 may detect time information, position information, energy information and direction information of a photon from an annihilation event. The photon signal can be converted into an electrical signal such as current or voltage by a photoelectric converter. An electronic acquisition system and a computer system may perform tasks including one or more of acquisition, analog/digital conversion, storage, calculation, and image reconstruction for the electrical signal to obtain images of the subject, such as one or more of cross-sectional, coronal, and sagittal images of organs of the subject. Tissues or lesions with a high metabolic rate exhibit relatively bright signals on a PET reconstructed image, and tissues or lesions with a low metabolic rate exhibit relatively dark signals on the PET reconstructed image.
NEUSOFT MEDICAL SYSTEMS CO., LTD. (NMS), founded in 1998 with its world headquarters in China, is a leading supplier of medical equipment, medical IT solutions, and healthcare services. NMS supplies medical equipment with a wide portfolio, including CT, Magnetic Resonance Imaging (MRI), digital X-ray machine, ultrasound, Positron Emission Tomography (PET), Linear Accelerator (LINAC), and biochemistry analyser. Currently, NMS' products are exported to over 60 countries and regions around the globe, serving more than 5,000 renowned customers. NMS's latest successful developments, such as 128 Multi-Slice CT Scanner System, Superconducting MRI, LINAC, and PET products, have led China to become a global high-end medical equipment producer. As an integrated supplier with extensive experience in large medical equipment, NMS has been committed to the study of avoiding secondary potential harm caused by excessive X-ray irradiation to the subject during the CT scanning process.